The present invention relates to electric sanders, and more particularly, to a combination belt sander and disc sander.
Electric sanders are usually one of two types. The first type, commonly referred to as a belt sander, contains an endless belt bearing an abrasive surface which moves along an endless horizontal pathway. Typically, the workpiece is placed upon the abrasive surface and manipulated in relation to the continuously moving belt, so as to expose the surface of the workpiece to the moving abrasive belt. Generally, the workpiece is placed on top of the belt. This type of sander is particularly suited for sanding the horizontal surface on a flat workpiece, for example, the top or bottom side of a flat workpiece. Therefore, depending upon the configuration of the workpiece or the area on the workpiece the user wants to sand, a horizontal belt sander may not be appropriate.
The second common type of sander is a disc sander which typically has a disc with an abrasive surface that rotates about a central axis. The disc is generally situated in a vertical plane relative to the workpiece and is commonly employed to sand the end or a side of a workpiece.
A typical user of power tools, who engages in woodworking or finishing, may find it necessary to use two different types of sanders, a belt sander and a disc sander, in order to adequately sand or finish a workpiece to a particular configuration. It would be an advantage, therefore, to have an electric sander device that employs both a belt sander and a disc sander.
Such a device is available, as shown in U.S. Design Pat. No. 293,763, so as to provide both types of sanders in a single device. A combined belt and disc sander of this type facilitates a woodworking operation by enabling the user to quickly use either the belt or disc sander in a single device. However, there are several disadvantages with this combined unit. Since the disc sander and belt sander are mounted on the same drive shaft, the disc sander necessarily obstructs the work area of the belt sander.
To optimally use a combined belt and disc sander, the top of the disc sander should be mounted below the belt sander, in order to provide an unobstructed work area, on and around the sanding belt when operating in a horizontal position. The supporting work table should also be capable of being used with both the disc sander as well as the belt sander when the belt sander is in a horizontal position. Furthermore, when used with the belt sander, the latter is capable of being moved to a vertical position, with the work table being movably mounted for use in conjunction with the vertically operating belt sander.
Moreover, to enhance the versatility of such a combination sander, the work table should be capable of angular adjustment relative to the either the disc or belt sander surface so that the supported workpiece can be placed at a desired angle for exposure to the sanding surface. For example, a beveled edge of a workpiece could be sanded at an appropriate angle if the work table can be adjusted angularly relative to the sander. Furthermore, the combination sander should have a motorized drive mechanism employing one electric motor that can drive both the belt sander and the disc sander, to enable the device to be easily and economically manufactured and assembled.